The adjustability of saws and other electric machine tools relative to the surface of a workbench has been a long-standing concern in the prior art.
More particularly, in applications such as the construction of roof trusses, where numerous members having a variety of different cuts and angles therein must be generated in large numbers, factors such as the mobility, portability, ease of adjustability and re-positioning of the tool, and weight of the system, are all important factors.
While numerical control machines have become commonplace in many machine tool areas, for example, machine drills, lathes, files, etching devices, and many other areas, a suitable numerical (or computer) control machine suitable for use with a power saw at a construction site in which the cutting of many wood members, having various angles, as in a roof truss structure, has not appeared in any practical or economic form.
Those efforts along these lines, known to the inventor, include a programmable turntable manufactured by Speed Cut, Inc., of Corvallis, Oreg. 97339, and the so-called SPIDA Radial Saw, also manufactured by Speed Cut. Comparable products are offered by a handful of other companies around the world.
Systems such as those of Speed Cut, Inc. involve considerable weight, occupy a large volume and ground area, are heavy, costly, are not easy to adjust or program, and are time-consuming to maintain. Also, they are not as easy or convenient to work with in the field as might be desired.
At a more technical level, systems such as those of Speed Cut make use of articulated arms which extend directly from a rotatable workbench associated with the cutting system. The shortcoming of this structure is that vertical loads upon the arms are transmitted to a rotatable workbench. Therefore a particularly robust structure is required, with the costs attendant thereto. Also, achievement of proper registration between the cutting tool and the cutting tool is complex where the workpiece is secured to a rotatable workbench. That is, loads on vertical bearings are not evenly distributed, this degrading accuracy of the saw blade. Understandably, systems of the above type also impart considerable wear on their moving parts.
It is, therefore, as a response to the above set forth long-felt need in the prior art that the invention is directed.